Subsurface deterioration in concrete structures presents a significant challenge for inspection and maintenance engineers. Cracking, delaminations and spalling that can occur as a result of corrosion of embedded reinforcing steel can lead to pot holes and even punch-through of concrete bridge decks. Concrete from overpass bridges can separate from the structure and fall into traffic below the bridge, presenting a safety hazard for motorists. This paper reports on efforts to develop effective methods of applying infrared (IR) imaging for the detection of subsurface damage in highway bridges. For reliable imaging, measurable temperature contrasts must exist between deteriorated and sound concrete. The study explores the challenges and benef ts of applying IR technology in the field, and methods for determining if the appropriate environmental conditions exist for accurate analysis.